The present invention relates to a cooling pack and, more particularly, to such a cooling pack comprising a coolant carrier obtained by dispersing and fixing liquid absorbent polymer particles on liquid absorbent substrate to keep said particles dispersed thereon, and a container adapted to enclose said coolant carrier.
It is well known, for example, from Japanese Disclosure Gazette Nos. 1987-267386 and 1987-240377 to utilize as a coolant carrier water absorbent polymers to obtain a cooling effect for a long duration and to avoid exudation of said polymer by fixing particles of said absorbent polymer to a suitable substrate. Such coolant carrier of prior art otherwise might be susceptible to said exudation or scattering and also to the occurrence of adhesive stickiness while in use and thawing of coolant. Accordingly, such a coolant carrier has usually been used in practice with an associated bag adapted to enclose said coolant carrier for improvement of shape stability as well as convenience of handling thereof.
With the articles of such nature, an adequate quantity of water is introduced into the bag so as to be held by absorbent polymer particles and then frozen prior to use. Means for introduction of water into said bag may be roughly classified into two types, i.e., a valve type means adapted for introduction of water into the sealed bag through a valve such as a check valve, and a dip type means adapted for introduction of water into the bag provided with a plurality of fine perforations or slits by immersing into water, through said fine perforations or slits. The valve type means for introduction of water has been found to be disadvantageous not only in that provision of the valve correspondingly increases the manufacturing cost thereof, but also in that it is impossible to introduce water into a plurality of said bags simultaneously, namely, water must be introduced into each of said bags one at a time. The dip type means allows water to be introduced into a plurality of said bags simultaneously, but is inconvenient in that a relatively long time is needed for introduction of water since a dimension of said fine perforations or slits is strictly limited to prevent leakage of the absorbent polymer particles possibly occurring before and after said water introduction, and also in that absorbent polymer particles tend to agglomerate to cause uneven water introduction into said bag.